Ch 33/34 MB

Which of the following statements about bilaterian animals is true?

All bilaterians are triploblastic

Which of the following statements about deuterostomes is false?

All deuterostomes exhibit radial symmetry in their bodies.

How does the structure of the digestive tract in different invertebrate groups affect the size of the organisms that they can eat? Match the terms in the left column to the appropriate blanks in the sentences on the right. Not all terms will be used.

Animals such as sponges and cnidarians have a central body cavity, not a digestive tract.In sponges, this central cavity is lined by cells that use phagocytosis to remove food particles from water drawn into the cavity. This allows eating relatively small organisms.In contrast, cnidarians push captured prey into their central cavity, where the prey are digested into components that can be absorbed by cells lining the cavity. This allows eating relatively large organisms.

Which phylum is characterized by animals that have a segmented body?

Arthropoda

Which evidence supports the hypothesis that four-limbed animals came from fish?`

Both fish and four-limbed animals are vertebrates. Fish and four-limbed animals have very similar embryos DNA analysis shows that fish are tetrapods' closest relatives. The fossil record shows more and more tetrapod-like fish before the appearance of tetrapods about 365 million years ago.

In Figure 33.2 in your textbook, which two main clades branch from the most recent common ancestor of the eumetazoans?

Cnidaria and Bilateria

Which two main clades branch from the most recent common ancestor of the eumetazoans?

Cnidaria and Bilateria

Which structure is not an innovation that occurred during vertebrate diversification?

Exoskeleton

True or false? An organism that is radially symmetric has many well-developed head regions.

False

Choose the class to which this animal belongs.

Mammalia

Which structure can be used for feeding and gas exchange?

Pharyngeal gill slit

Which of the following combinations of phylum and description is correct?

Platyhelminthes−−flatworms, gastrovascular cavity, no body cavity

Based on the phylogenetic tree shown here, identify the basal taxon of metazoans (animals).

Porifera

The animal phylum most like the protists that gave rise to the animal kingdom is _____. See Concept 33.1 (Page)

Porifera

Which of the following combinations of phylum and description is incorrect?

Porifera-gastrovascular cavity, coelom present

What evidence suggests that vertebrates are more closely related to echinoderms than are any other invertebrate phyla

Shared DNA sequences Submit

Which of the following statements about vertebrates is true?

The development of an amniotic egg and internal fertilization allowed vertebrates to reproduce away from water.

Which characteristics define a chordate?

The presence of four specific morphological traits

How did the great transition from fish to tetrapod occur?

The transition occurred gradually over time, so there are many intermediate forms.

Which characteristic distinguishes echinoderms from the other two deuterostome lineages?

Their body plan

Which of the following statements correctly describes a characteristic of the phylum Platyhelminthes?

They are dorsoventrally flattened

Which of the following is characteristic of the phylum Platyhelminthes? See Concept 33.3 (Page)

They are dorsoventrally flattened.

Why did Shubin and Daeschler search in the Canadian arctic for fossil evidence of the transition from fish to tetrapods?

They hypothesized that the transitional fossils were in sedimentary rocks older than 365 million years ago, when the first tetrapods appear in the fossil record.

Which of the following is true of annelids? See Concept 33.3 (Page)

They perform gas exchange across their skin.

Which of the following statements is true of annelids?

They perform gas exchange across their skin.

What kind of habitat did tiktaalik live in?

Tiktaalik lived in a warm, freshwater swamp.

What is a transitional fossil?

Transitional fossils have features that are intermediate between ancestors and descendants.

Evolutionary reversals (character losses) are also common among living members of a vertebrate lineage and early members of the lineage. Choose examples that illustrate this observation. Select the three correct statements.

Whales and snakes lack legs.Living birds lack teeth.Most mammals lack shelled eggs

Vertebrates and tunicates share

a notochord and a dorsal, hollow nerve cord.

Which of the following could be considered the most recent common ancestor of living tetrapods?

a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates

Which of the following chordates is most likely to look the least like other chordates?

adult tunicate

Listed below are four adaptations of terrestrial vertebrates. Which choice is a characteristic only of truly terrestrial animals with no need to return to water at any stage of the life cycle?

amniotic eggs

Most members of which of the following groups are most closely associated with a wet (or moist) environment?

amphibians

The diagnostic feature of Chondrichthyes is __________.

an endoskeleton of cartilage

A marine biologist dredges up a small animal from the bottom of the ocean. It is uniformly segmented, with short, stiff appendages and soft, flexible skin. It has a complete digestive system and a closed circulatory system, plus multiple true coeloms. Based on this description, it may be determined that the animal must be a(n) __________.

annelid

A marine biologist dredges up a small animal from the bottom of the ocean. It is uniformly segmented, with short, stiff appendages and soft, flexible skin. It has a complete digestive system and a closed circulatory system, plus multiple true coeloms. Based on this, you determine that the animal must be a(n) _____. See Concept 33.3 (Page)

annelid

Members of the phylum Mollusca _____. See Concept 33.3 (Page)

are soft-bodied and often covered by a shell

Members of the phylum Mollusca __________.

are soft-bodied and often covered by a shell

What is the evolutionary cause of such changes?

descent with modification

Living members of a vertebrate lineage can be very different from early members of the lineage. Choose examples that illustrate this observation.

early reptiles with four legs and living snakes that lack legs early reptiles with four legs and living birds with two legs

The water vascular system of echinoderms

functions in locomotion and feeding

Which of the following is a characteristic of cnidarians?

gastrovascular cavity

Which of the following is a characteristic of cnidarians? See Concept 33.2 (Page)

gastrovascular cavity

Unlike eutherians, both monotremes and marsupials

have some embryonic development outside the uterus

Tiktaalik had a combination of fishlike and tetrapod-like characteristics. Which were the tetrapod-like characteristics?

interlocking ribs flat head with eyes on top a neck

A land snail, a clam, and an octopus all share

mantle

There are three major groups of mammals, categorized on the basis of their _____. See Concept 34.6 (Page)

method of reproduction

Neural crest cells appear on the edges of the neural tube and spread throughout the embryo, giving rise to all of the following structures except __________.

pharyngeal slits (or clefts) of invertebrate chordates

Which of the following is a tetrapod? Select all that apply.

reptile, mammal, bird, and amphibian

Which of the following are thought to be most closely related to humans?

sea stars

Which of the following are thought to be most closely related to humans? See Concept 33.5 (Page)

sea stars

All of the following represent diagnostic features of chordates except for which one?

vertebrae

Why have we NOT found examples in the fossil record of every animal that ever lived on Earth?

-To become a fossil, an animal must remain buried for thousands or millions of years until it (and the layer around it) turns to rock. -Many fossils remain buried. We can only find them when they are exposed by erosion or excavation. -To become a fossil, an animal must be quickly and completely buried in ash or sediment before it has a chance to decompose.